There has been known a vehicle lamp in which light emitted from a light source is reflected toward a front of the lamp by a reflector so as to form a low-beam light distribution pattern.
JP-A-2016-72017 describes a vehicle lamp in which a light source includes a first light emitting element and a second light emitting element which is arranged at a lamp front side of the first light emitting element.
The vehicle lamp described in JP-A-2016-72017 is configured such that a light distribution pattern configuring a part of a low-beam light distribution pattern is formed by turning on the first light emitting element, and a light distribution pattern configuring a part of a high-beam light distribution pattern is formed by turning on the second light emitting element.
It is desired to enhance brightness of a lower vicinity region of a cut-off line on an oncoming vehicle lane side in the low-beam light distribution pattern so as to improve forward visibility when a vehicle travels on a curved path curved toward the oncoming vehicle lane side with a low beam.
In the vehicle lamp described in JP-A-2016-72017, when forming the light distribution pattern configuring a part of the low-beam light distribution pattern by turning on the first light emitting element, it is conceivable to use a part of a reflecting surface of the reflector as a dedicated region for enhancing the brightness of the lower vicinity region of the cut-off line on the oncoming vehicle lane side.
In this case, if a reflecting region in the reflecting surface of the reflector which is positioned in a surface normal direction of a light emitting surface of the first light emitting element is used as the dedicated region, a light distribution pattern for enhancing the brightness of the lower vicinity region of the cut-off line on the oncoming vehicle lane side can be formed as a bright light distribution pattern.
However, since such a reflecting region is positioned relatively closer to the first light emitting element, a light source image formed by the reflected light becomes large and the light distribution pattern also has a large vertical width. For this reason, it is difficult to form the light distribution pattern for enhancing the brightness of the lower vicinity region of the cut-off line on the oncoming vehicle lane side as a light distribution pattern having a small vertical width, and it is difficult to finely control a forming position thereof. Therefore, it is difficult to improve the forward visibility when a vehicle travels on a curved path curved toward the oncoming vehicle lane side, without giving glare to a driver of an oncoming vehicle.
Meanwhile, if a reflecting region positioned near a front end edge of the reflecting surface of the reflector were used as the dedicated region, the reflecting region would be positioned farthest from the first light emitting element, so that it is possible to form a small light source image by the reflected light. Therefore, the light distribution pattern for enhancing the brightness of the lower vicinity region of the cut-off line on the oncoming vehicle lane side can be formed as a light distribution pattern having a small vertical width.
However, since such a reflecting region is positioned greatly away from the surface normal direction of the light emitting surface of the first light emitting element, and a sufficient amount of reflected light cannot be obtained, it is still difficult to improve the forward visibility when a vehicle travels on the curved path curved toward the oncoming vehicle lane side.